Gov. Peter Shumlin and others threw the switch on the system Thursday, inaugurating the 157-kilowatt solar array, the largest such system at a school in the state.

Shumlin was joined by state and local officials and representatives of the solar power company the installed the array, SunCommon, and Green Mountain Power, Vermont's largest electric utility.

"The school gets this project built for free," said Luke Shullenberger, principal at Green Mountain Capital, which financed the $550,000 installation. "They've no exposure to ownership, no upfront money, and no investment to make."

The 480-panel array can produce enough electricity for about 30 homes. Surplus electricity will be sold to Green Mountain Power, with proceeds returned to the school.

"We're saving $6,000 a year in energy," said Tom Drake, the school principal. "That's some new computers - not a great deal of money but for me the learning opportunity is priceless."